Have you ever had the tire pressure sensor fault come up on your car’s dash? If you were confused about the cause and unsure how to fix it, don’t worry you wouldn’t be alone.
The good news is there is no need to start panicking if you see this message pop up. Usually the problem is not related to the tires themselves but rather the sensor which monitors them. So, after quickly pulling over and checking for any flat tires, it is usually fine to continue driving your car.
It is more common to receive this tire pressure sensor fault on modern or luxury cars. They can contain many complicated diagnostic and monitoring systems which are unfortunately prone to failure from time to time. The more complicated the car’s electronics, the greater the chance of something going wrong.
What is a Tire Pressure Sensor Fault?
The tire pressure sensor is a small processing chip contained within the tire. It’s purpose is to send an alert to the driver in case the tire pressure is outside the safe limits for the specific tire. In fact, these tire pressure sensors have been a legal requirement for almost 15 years in the USA.
So, whether you accidentally over-inflate your tires at the gas station, or they suddenly lose pressure due to a puncture, you will receive a tire pressure sensor fault pop up on the dash. In addition, you will receive the fault alert if the sensor itself is damaged or malfunctioning.
Depending on the brand and model of vehicle you drive, the actual message may pop in text, or as a yellow exclamation mark. If you receive this fault you should immediately pull over in a safe manner and check for any flat tires.
Tell-Tale Symptoms of a Tire Pressure Sensor Fault
If you somehow miss the tire pressure sensor fault message pop up on your car dashboard, then there are 3 major symptoms of the problem.
Check Engine Light Illuminated
The check engine light will usually come on in addition to the tire pressure sensor fault message. In fact this this light will come on for a host of reasons. It is a signal to you, the driver, that there is something wrong with your car that needs to be fixed.
So, if you see this light, make sure to check closely whether the TPMS light is also illuminated.
Tires Are Wearing Out Unevenly
In most cases, uneven tire wear is caused by inflating your tires to the wrong pressure. Over-inflation will cause the centre of your tires to wear faster than the edges, while under-inflation will cause the edges to wear faster.
If you notice uneven wear on your tires, it is extremely likely that they are inflated to the wrong pressure. In this case, even if you don’t have the tire pressure sensor fault going off, you should double check the pressure levels.
Less Miles Per Gallon
It is usually more likely that your tires will be under-inflated rather than over. When this is the case, it causes the tires to drag and decrease their efficiency. This in turn will cause your car’s engine to need more power to travel the same distance.
The excess drag will lower your fuel efficiency significantly. The lower the tire pressure, the more magnified this problem will become. So, if you notice you are getting less miles per gallon, this is a big sign that your tire pressure sensor may be faulty.
The Usual Reasons for Tire Pressure Sensor Faults
The causes for a tire pressure sensor fault can vary depending on the type of vehicle you drive and the conditions it is exposed to. Some vehicles will have causes specific to the model but here are some more general reasons.
By far, the most common cause for a tire pressure sensor fault is low tire pressure. The sensor’s main function is to detect this under-inflation, so, no surprises here.
On each tire is fitted a pressure sensor which constantly monitors the inflation level of it’s tire. If the tire pressure falls below the sensor’s preset limit, it will send an alarm to your car to warn you.
Problems With the Tire Pressure Management System
If the tire pressure management system of your car malfunctions, then it probably means your tires themselves are fine. You will receive the tire pressure sensor fault but the problem will be with the electronics.
In some modern cars the TPMS can be quite complicated. With complication comes fragility and unfortunately these things tend to break down quite often. Worse, still the exact problem can be very difficult to diagnose due to the various interactions and dependencies of different systems.
Faulty Wiring of the TPMS
There is a plethora of different cables and wires within modern vehicles and mixing them up is something that happens all the time. It’s an easy mistake to make and can cause short circuits and malfunctions.
The TPMS is not immune to this problem and a mix up in the wiring is another cause for a tire pressure sensor fault. Diagnosing this reason for the error can be a total nightmare, you better hope that your car is under warranty.
Tire Pressure Sensor Has Expired
Another common cause of a tire pressure sensor fault is simply when the tire pressure sensors have worn out. Over time the sensor is exposed to harsh conditions and may start to corrode, leading it to malfunction. This will depend on the materials used in the valve stem and the overall manufacturing quality.
There is also the possibility that the small battery that supplies the pressure sensor with power has expired. Usually these batteries will last 5 or 6 years, so it probably a good time to change your tires anyway if this happens.
How to Reset Tire Pressure Sensor
Resetting a tire pressure sensor fault can be accomplished in a variety of ways depending on what caused it to activate. So, you should try these next steps and check whether the fault turns off or not after each one.
Check The PSI of Your Tires
Absolutely the first thing you should do is check what pressure your tires are reading and make sure they are inflated to within the manufacturer specifications. Check each tire in turn with a pressure gauge and either let some air out if it’s over, or add a little extra if under.
One thing to note is your front and rear tires may have different recommended pressures. This is especially likely on some high performance vehicles with larger wheels at the rear. In any case, the recommended pressure should be listed on the tire’s sidewall.
Power Cycle The Tire Pressure Management System
It’s possible that your vehicle comes with an inbuilt function or switch to reset the tire pressure management system. If this is the case you can easily try resetting and see if the sensor fault goes away.
Make sure to read through your vehicle’s manual carefully and see whether this function exists and, if so, how to activate it.
Calibrate the Sensors
There is a little device on each of your car’s wheels, called a transponder. These transponders report the rotated position of your wheels to the tire pressure management system for a variety of reasons.
If you rotate your car’s wheels then the TPMS will need to re-learn the correct positions. This may sometimes lead to a tire pressure sensor fault and the need to re-calibrate.
You will need to refer to your vehicles manual and perform the transponder re-calibration procedure carefully. You should replace the valve stems at the same time as they can be sensors themselves.
Disconnect Your Vehicle’s Battery
If the other methods haven’t worked for you, then you can try resetting your vehicle’s computer system completely. The simplest way to do this is usually disconnect the battery for a few minutes so that everything electrical reboots.
Simply open the hood and disconnect the battery terminals. Afterwards, turn on a cabin light and wait for it to go out. Your car should be completely drained of power at this point so you can go ahead and reconnect the battery.
Hopefully, after the computer system has reset, your tire pressure sensor fault will have cleared itself.
Use an OBD2 Tool to Reset the Sensor Fault
For this method you will require an additional tool, an OBD2 scanner. This device will connect to your vehicle’s computer system and read out diagnostic data. It’s then just a matter of resetting these fault codes and hoping that they don’t immediately reappear.
The difficulty of this method varies both with the model of your car and the type of OBD2 scanner you use. You will need to do a little bit of research to understand how to use it correctly.
Take It to a Mechanic
If you have tried all the above steps without success then it might be time to through in the towel and book your car in to be inspected. The underlying problem may be caused by a wiring or electrical fault that you won’t be able to diagnose.
Summing It All Up
As you have seen, a tire pressure sensor fault can pop up for a variety of reasons. You should go through the list supplied in this article and try to diagnose the root cause of the fault in your vehicle.
Most of the solutions are simple to perform by yourself, especially if you have access to an OBD2 tool to read the diagnostic data. The most likely cause will always be tire under-inflation, and this is obviously very easy to fix.
If it’s the case that you have a more complicated problem due to an electrical fault or short circuit, then it’s best to just take it in for a service by your mechanic.